Improvement in dryjng-kilns



UNITED STATES PATENT OFFICE DAVID BONNELL, OF ST. JOSEPH, MICHIGAN.

IMPRovEME'NT |N DRviNG-KILNS.

Specification forming part of Letters Patent No. 169,230, dated October26, 1875; application filed March 2:2, 1875.

To all whom 'it may concern Be it known that I, DAVID BONNELL, of St.Joseph, Berren county, and State of Michigan, have invented a new anduseful Improvement iu Drying-Kilns, ot' which the following is adescription:

This invention relates, in its nature, to a device for drying lumber andother substances by means of artificial heat, the object being toaccomplishvthe purpose with greater etliciency and economy than hashitherto been done.

The accompanying drawing forms a part of this specification, and theletters of reference marked thereon indicate the parts referred to by asimilar letter in the written part of this specitication, in which- Arepresents the furnace or heater 5 but this maybe any suitable devicefor heating air, and need not be describedin full here. B B representinduction-tubes. These tubes convey heated air from the heater to thedryingchamber O, entering said chamber at a point above midway of itsheight. This chamber may be of any suitable form of construction thatwill admit of being shut tight, and need not differ materially fromdrying-kilns in common use. E E represent eduction pipes. These pipesare placed at the bottom of the drying-chamber G, with their open mouthsnear the cent-ral part of the bottom, or may be extended over the entirebottom, in which case they should be perforated, so as to draw the airfrom all parts of the bottom of said chamber. The outer ends oftheeductionpipes pass out through the Wall of the dryingchamber, andconnect to the opposite sides of the case of the rotary fau F. This fanis of the ordinary construction of rotary exhaustfans, and is driven byany suitable motive power. The office of this fan is to exhaust thehumid air from the drying-chamber, thus producing a partial vacuum,which will be supplied by hot dry air through the inductiontubes B B,and causing a -downward current of hot air through the drying-chamber.The constant discharge of humid air through the eduction-pipes will givegreater effect to the incoming hot air, and the fan F will answer thethreefold purpose of producing a draft through the heater, a downwardcurrent of hotair through the drying-chamber, and of expelling the humidair from the bottom.

Having thus describedl my invention in the most exact terms that I cangive, what Iclaim as new, and desire to secure by Letters Patent, is--The drying-chamber O, having the induction-tubes B B, introduced at apoint above midway of its height, and provided at the bottom with theeducation-pipes E E, in combination with the fan F, as and for thepurposes hereinbefore set forth.

DAVID B'oNNELL.

